Improving the mechanical properties of Grade 45 steel and evaluating the feasibility of using Cr-Mo steels for ball rolling mill guide shoes

Enhancing the mechanical properties of guide shoes in ball rolling mills (BRM) directly contributes to increasing the service life of these components. This study examines various methods for improving durability, ranging from hard facing with wear-resistant alloys to optimizing heat treatment parameters and replacing conventional Grade 45 structural steel with alloyed wear-resistant grades. The research focuses on the surface hardening of Grade 45 steel guide shoes using liquid ferritic nitrocarburizing (carbonitriding) and evaluates the potential of replacing them with 55Cr2MoL alloy steel. The relevance of this work is driven by increasing requirements for the operational resource of rolling equipment under conditions of higher rolling speeds and more severe operating environments. Based on the analysis of the base material properties and thermal strengthening results, changes in strength, hardness, and wear resistance of the guiding elements were evaluated under various processing regimes. Comparative analysis between Grade 45 steel and chromium-molybdenum steels allowed for assessing their potential as alternative materials for guide units. It is demonstrated that the implementation of Cr-Mo steels can significantly increase the unit's resource and operational reliability due to their superior resistance to abrasive wear and thermal loads. The findings of this study can be applied to the modernization of ball rolling mills and the selection of structural materials for equipment operating under combined thermal and mechanical stress.